SQL Server-在表中查找重復項

Question

我們有近100+百萬行的大表。 有人可以幫助您如何在表格中查找重復數據並將其移至ARCHIVE

表名稱：CustomerData
字段數：10

應該保留最后一個（由END_DATE標識為該記錄中的NULL）

問候

Answer 1

您只需要移動END_DATE不為NULL的行？

在單筆交易中：

INSERT INTO archive (column1, column2, ... column10)
SELECT column1, column2, ..., column10
FROM CustomerData
WHERE END_DATE IS NOT NULL

DELETE CustomerData
WHERE END_DATE IS NOT NULL

Answer 2

假設CustomerData表的結構為：CustomerDAta（cust_id，Cust_name，Address_ID，start_time，End_Date，.....，其他7列）；

並假設有2位客戶具有SAme地址ID以獲取重復項。

插入存檔表：

INSERT INTO archive (column1, column2, ... column10)
SELECT cust_id, start_Date, ...,End_Date
FROM CustomerData
WHERE END_DATE IS NOT NULL 
AND Address_ID IN(
        SELECT Address_ID FROM
            (
            SELECT Address(ID),count(Address_ID)
            FROM customerDAta
            GROUP BY Address_ID
            HAVING count(Adddress_ID)>1
            )
        )                       
                        )

要刪除自：-CustomerDAt表：-

DELETE CustomerData
WHERE END_DATE IS NOT NULL
    AND
    Address_ID IN(
            SELECT Address_ID FROM
            (
            SELECT Address(ID),count(Address_ID)
            FROM customerDAta
            GROUP BY Address_ID
            HAVING count(Adddress_ID)>1
            )
        )

INNER子查詢以提取與Oracle數據庫提供的employees表中的DeptID列相似的相同Address_ID列上的重復項。